/[svn]/linuxsampler/trunk/src/voice.h
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Annotation of /linuxsampler/trunk/src/voice.h

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Fri Dec 26 16:39:58 2003 UTC (20 years, 4 months ago) by schoenebeck
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* implemented looping; RAM only loops (that is loops that end within the
  cached part of the sample) are handled in src/voice.cpp whereas
  disk stream looping is handled in src/stream.cpp and is mostly covered
  there by the new ReadAndLoop() method in class 'Sample' from src/gig.cpp

1 schoenebeck 9 /***************************************************************************
2     * *
3     * LinuxSampler - modular, streaming capable sampler *
4     * *
5     * Copyright (C) 2003 by Benno Senoner and Christian Schoenebeck *
6     * *
7     * This program is free software; you can redistribute it and/or modify *
8     * it under the terms of the GNU General Public License as published by *
9     * the Free Software Foundation; either version 2 of the License, or *
10     * (at your option) any later version. *
11     * *
12     * This program is distributed in the hope that it will be useful, *
13     * but WITHOUT ANY WARRANTY; without even the implied warranty of *
14     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
15     * GNU General Public License for more details. *
16     * *
17     * You should have received a copy of the GNU General Public License *
18     * along with this program; if not, write to the Free Software *
19     * Foundation, Inc., 59 Temple Place, Suite 330, Boston, *
20     * MA 02111-1307 USA *
21     ***************************************************************************/
22    
23     #ifndef __VOICE_H__
24     #define __VOICE_H__
25    
26     #include "global.h"
27     #include "diskthread.h"
28     #include "ringbuffer.h"
29     #include "stream.h"
30     #include "gig.h"
31    
32     #define MAX_PITCH 4 //FIXME: at the moment in octaves, should be changed into semitones
33 schoenebeck 18 #define USE_LINEAR_INTERPOLATION 1 ///< set to 0 if you prefer cubic interpolation (slower, better quality)
34 schoenebeck 9
35     class Voice {
36     public:
37 schoenebeck 12 // Attributes
38 schoenebeck 15 int MIDIKey; ///< MIDI key number of the key that triggered the voice
39     Voice** pSelfPtr; ///< FIXME: hack to be able to remove the voice from the active voices list within the audio thread, ugly but fast
40     uint ReleaseVelocity; ///< Reflects the release velocity value if a note-off command arrived for the voice.
41 schoenebeck 12
42 schoenebeck 9 // Methods
43     Voice(DiskThread* pDiskThread);
44     ~Voice();
45     void Kill();
46     void RenderAudio();
47 schoenebeck 18 int Trigger(int MIDIKey, uint8_t Velocity, gig::Instrument* Instrument);
48 schoenebeck 9 inline bool IsActive() { return Active; }
49     inline void SetOutput(float* pOutput, uint OutputBufferSize) { this->pOutput = pOutput; this->OutputBufferSize = OutputBufferSize; }
50     private:
51     // Types
52     enum playback_state_t {
53     playback_state_ram,
54     playback_state_disk,
55     playback_state_end
56     };
57    
58     // Attributes
59 schoenebeck 26 float Volume; ///< Volume level of the voice
60 schoenebeck 9 float* pOutput; ///< Audio output buffer
61     uint OutputBufferSize; ///< Fragment size of the audio output buffer
62 schoenebeck 26 double Pos; ///< Current playback position in sample
63     double CurrentPitch; ///< Current pitch depth (number of sample points to move on with each render step)
64     gig::Sample* pSample; ///< Pointer to the sample to be played back
65     gig::Region* pRegion; ///< Pointer to the articulation information of the respective keyboard region of this voice
66     bool Active; ///< If this voice object is currently in usage
67 schoenebeck 9 playback_state_t PlaybackState; ///< When a sample will be triggered, it will be first played from RAM cache and after a couple of sample points it will switch to disk streaming and at the end of a disk stream we have to add null samples, so the interpolator can do it's work correctly
68     bool DiskVoice; ///< If the sample is very short it completely fits into the RAM cache and doesn't need to be streamed from disk, in that case this flag is set to false
69 schoenebeck 26 Stream::reference_t DiskStreamRef; ///< Reference / link to the disk stream
70 schoenebeck 9 unsigned long MaxRAMPos; ///< The upper allowed limit (not actually the end) in the RAM sample cache, after that point it's not safe to chase the interpolator another time over over the current cache position, instead we switch to disk then.
71 schoenebeck 26 bool RAMLoop; ///< If this voice has a loop defined which completely fits into the cached RAM part of the sample, in this case we handle the looping within the voice class, else if the loop is located in the disk stream part, we let the disk stream handle the looping
72     int LoopCyclesLeft; ///< In case there is a RAMLoop and it's not an endless loop; reflects number of loop cycles left to be passed
73 schoenebeck 9
74     // Static Attributes
75 schoenebeck 26 static DiskThread* pDiskThread; ///< Pointer to the disk thread, to be able to order a disk stream and later to delete the stream again
76 schoenebeck 9
77     // Methods
78 schoenebeck 26 void Interpolate(sample_t* pSrc);
79     void InterpolateAndLoop(sample_t* pSrc);
80     inline void InterpolateOneStep_Stereo(sample_t* pSrc, int& i, float& effective_volume) {
81     int pos_int = double_to_int(this->Pos); // integer position
82     float pos_fract = this->Pos - pos_int; // fractional part of position
83     pos_int <<= 1;
84    
85     #if USE_LINEAR_INTERPOLATION
86     // left channel
87     this->pOutput[i++] += effective_volume * (pSrc[pos_int] + pos_fract * (pSrc[pos_int+2] - pSrc[pos_int]));
88     // right channel
89     this->pOutput[i++] += effective_volume * (pSrc[pos_int+1] + pos_fract * (pSrc[pos_int+3] - pSrc[pos_int+1]));
90     #else // polynomial interpolation
91     // calculate left channel
92     float xm1 = pSrc[pos_int];
93     float x0 = pSrc[pos_int+2];
94     float x1 = pSrc[pos_int+4];
95     float x2 = pSrc[pos_int+6];
96     float a = (3 * (x0 - x1) - xm1 + x2) / 2;
97     float b = 2 * x1 + xm1 - (5 * x0 + x2) / 2;
98     float c = (x1 - xm1) / 2;
99     this->pOutput[i++] += effective_volume * ((((a * pos_fract) + b) * pos_fract + c) * pos_fract + x0);
100    
101     //calculate right channel
102     xm1 = pSrc[pos_int+1];
103     x0 = pSrc[pos_int+3];
104     x1 = pSrc[pos_int+5];
105     x2 = pSrc[pos_int+7];
106     a = (3 * (x0 - x1) - xm1 + x2) / 2;
107     b = 2 * x1 + xm1 - (5 * x0 + x2) / 2;
108     c = (x1 - xm1) / 2;
109     this->pOutput[i++] += effective_volume * ((((a * pos_fract) + b) * pos_fract + c) * pos_fract + x0);
110     #endif // USE_LINEAR_INTERPOLATION
111    
112     this->Pos += this->CurrentPitch;
113     }
114     inline void InterpolateOneStep_Mono(sample_t* pSrc, int& i, float& effective_volume) {
115     int pos_int = double_to_int(this->Pos); // integer position
116     float pos_fract = this->Pos - pos_int; // fractional part of position
117    
118     #if USE_LINEAR_INTERPOLATION
119     float sample_point = effective_volume * (pSrc[pos_int] + pos_fract * (pSrc[pos_int+1] - pSrc[pos_int]));
120     #else // polynomial interpolation
121     float xm1 = pSrc[pos_int];
122     float x0 = pSrc[pos_int+1];
123     float x1 = pSrc[pos_int+2];
124     float x2 = pSrc[pos_int+3];
125     float a = (3 * (x0 - x1) - xm1 + x2) / 2;
126     float b = 2 * x1 + xm1 - (5 * x0 + x2) / 2;
127     float c = (x1 - xm1) / 2;
128     float sample_point = effective_volume * ((((a * pos_fract) + b) * pos_fract + c) * pos_fract + x0);
129     #endif // USE_LINEAR_INTERPOLATION
130    
131     this->pOutput[i++] += sample_point;
132     this->pOutput[i++] += sample_point;
133    
134     this->Pos += this->CurrentPitch;
135     }
136 schoenebeck 9 inline int double_to_int(double f) {
137     #if ARCH_X86
138     int i;
139     __asm__ ("fistl %0" : "=m"(i) : "st"(f - 0.5) );
140     return i;
141     #else
142     return (int) f;
143     #endif // ARCH_X86
144     }
145     };
146    
147     #endif // __VOICE_H__

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